1. Field of the Invention
The invention relates to a composition for producing coatings containing dialkyl ethers as an additive and it relates to the use of such compositions in coatings as well as coatings produced in this way.
2. Description of Prior Art
It is known that additives are used to improve the properties of paints and varnishes. A wide variety of substances, for example, waxes, are known and used as additives. Waxy varnish additives may be introduced in the form of wax-coated solid particles, which often act as delustering agents.
DE 1006100 B (corresponds to U.S. Pat. No. 2,838,413) discloses the production of a delustering agent of silicic acid hydrogels, which are dried, activated at elevated temperatures and impregnated with a petroleum wax of the chain length C50 to C60 with a low acid number, iodine number and saponification number as well as with a melting point above 80° C.
U.S. Pat. No. 3,816,154 describes the use of wax-coated silica gels as delustering agents in varnishes. The wax is applied to the silica gel particles either as a melt coating or as an emulsion coating. If the silica gel is coated with waxes and fatty acids at the same time, a better dispersibility and better light scatter properties are found. The additive composition is milled in a jet mill to a particle size of 2 μm to 10 μm, wherein the wax is a petroleum or polyolefin wax and the fatty acid used has a chain length of C12 to C18.
US 2001/0006993 discloses a dry-mixed additive consisting of one or more film-forming polymeric components and one or more carrier components based on alumina, aluminum hydroxide, wax-coated silica gel or a combination thereof. This additive is being promoted as a gloss-reducing agent.
EP 1095111 describes a powder varnish composition in which a wax-coated silicon dioxide in finely divided form is added as an additive by a dry mixing method wherein it may also contain aluminum oxide and aluminum hydroxide. The waxes used are natural animal wax (for example, beeswax and lanolin) or natural vegetable waxes (for example, carnauba wax), petroleum waxes (for example, paraffin wax, microcrystalline wax) or synthetic waxes (for example, polyethylene, polyol ether esters). In addition, long-chain esters and hydrocarbons may be used.
U.S. Pat. No. 5,356,971 discloses that synthetic or natural wax added to powder coatings creates better lubricant properties and water repellency. No negative effect on the weather resistance is observed. The melting point of the wax should be in the range of 50° C. to 280° C. and ideally is 10° C. to 20° C. below the processing temperature. The group of waxes comprises natural animal, vegetable and petroleum waxes or mineral waxes as well as long-chain esters. If pure wax is used, it has a negative effect on the adhesion of the powder coating to metal at higher wax contents (for example, >10 wt %). If a supported wax is used, the scratch resistance suffers a negative effect of more than 15% even at load levels of more than 15%.